DESCRIPTION
The M35501FP generates digit signals for fluorescent display
when connected to the output port of a microcomputer. There are
up to 16 digit pins available, and more can be added by connect-
ing additional M35501FPs. The number of fluorescent displays
can be increased easily by connecting the M35501FP to the
CMOS FLD (VFD; Vacuum Fluorescent Display) output pins of an
8-bit microcomputer in MITSUBISHI's 38B5 Group. The
M35501FP is suitable for fluorescent display control on household
electric appliances, audio products, etc.
Outline: 24P2E-A
24-pin plastic-molded SSOP
PIN CONFIGURATION (TOP VIEW)
M35501FP
FLD (VFD) DIGIT EXPANDER
MITSUBISHI IC'S
Fig. 1 Pin configuration of M35501FP
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
M35501FP
SEL
CLK
V
SS
V
CC
OVF
IN
OVF
OUT
DIG
15
DIG
14
DIG
13
DIG
12
DIG
11
DIG
10
DIG
8
DIG
9
DIG
7
DIG
6
DIG
5
DIG
4
DIG
3
DIG
2
DIG
1
DIG
0
V
EE
RESET
FEATURES
q
Digit output ............................................................. 16 (maximum)
Up to 16 pins can be selected
More digits available by connecting additional M35501FPs
Output structure: high-breakdown voltage, P-channel open-
drain; built-in pull-down resistor between digit output pins and
VEE pin
q
Power-on reset circuit ........................................................ Built-in
q
Power source voltage ................................................ 4.0 to 5.5 V
q
Pull-down power source voltage ................................ Vcc 43 V
q
Operating temperature range ................................... 20 to 85 C
q
Package ............................................................................. 24P2E
q
Power dissipation ............... 250
W (at 100 kHz operation clock)
2
M35501FP
FLD (VFD) DIGIT EXPANDER
MITSUBISHI IC'S
FUNCTIONAL BLOCK
Fig. 2 Functional block diagram
PIN DESCRIPTION
Table 1 Pin description
Pin
V
CC
, V
SS
RESET
CLK
SEL
OVF
IN
OVF
OUT
DIG
15
DIG
0
V
EE
Name
Power source input
Reset input
Clock input
Select input
Overflow signal input
Overflow signal output
Digit output
Pull-down power source input
Function
Apply 4.05.5 V to Vcc, and 0V to Vss.
Reset internal shift register (built-in power-on reset
circuit).
Digit output varies according to rising edge of clock
input.
Use when specifying the number of digits.
Input "H" when using one M35501FP. Connect to
OVF
OUT
pin of additional M35501FPs when using
multiple M35501FPs (to use 17 digits or more).
Leave open when using one M35501FP. Connect to
OVF
IN
pin of additional M35501FPs when using multiple
M35501FPs (to use 17 digits or more).
Output the digit output waveform of fluorescent
display. Leave open when not in use (V
EE
level
output).
Apply voltage to DIG
0
DIG
15
pull-down resistors.
Output Structure
CMOS input level
Built-in pull-up resistor
CMOS input level
Built-in pull-down resistor
CMOS input level
Built-in pull-down resistor
CMOS input level
CMOS output
High-breakdown-voltage
P-channel open-drain output
Built-in pull-down resistor
Fig. No.
3
2
2
4
5
1
V
EE
DIG
15
DIG
14
DIG
13
DIG
12
DIG
11
DIG
10
DIG
9
DIG
8
DIG
7
DIG
6
DIG
5
DIG
4
DIG
3
DIG
2
DIG
1
DIG
0
24
5
2
7
6
3
1
4
Power-on
reset
Optional digit
counter
Shift register
OVF
OUT
OVF
IN
V
CC
V
SS
RESET
CLK SEL
23
22
21
20
19
18
17
16
15
14
13
12
11
10
9
8
3
M35501FP
FLD (VFD) DIGIT EXPANDER
MITSUBISHI IC'S
PORT BLOCK
Fig. 3 Port block diagram
(1) DIG
0
DIG
15
V
EE
Pull-up transistor
Pull-down transistor
(2) SEL, CLK
(3) RESET
(4) OVF
IN
(5) OVF
OUT
Shift register
Shift register
4
M35501FP
FLD (VFD) DIGIT EXPANDER
MITSUBISHI IC'S
USAGE
Three usages of the M35501FP are described below.
(1) 16-Digit Mode: 16 digits selected
The number of digits is set to 16 by fixing the OVF
IN
pin to "H" and
the SEL pin to "L." Figure 5 shows the output waveform.
(2) Optional Digit Mode: 1-16 digits selectable
When the number of CLK pin rising edges during an "H" period of
the SEL pin is n and the OVF
IN
pin is fixed to "H," the number of
digits set is n. If n is 16 or more, all 16 digits are set. Figure 6
shows the output waveform.
Fig. 4 Digit setting
(3) Cascade Mode: 17 digits or more selectable
17 digits or more can be used by connecting two M35501FPs or
more. Figure 7 shows an example using three M35501FPs, offering
33 to 48 digit outputs.
Cascade mode will not operate if all M35501FPs are in 16-digit
mode (SEL = "L"). Use the most significant M35501FP in the optional
digit mode for DIG output. Figure 8 shows the output waveform.
SEL pin
CLK pin
n
5
M35501FP
FLD (VFD) DIGIT EXPANDER
MITSUBISHI IC'S
DIGIT OUTPUT WAVEFORM
Fig. 5 16-digit mode output waveform
Fig. 6 Optional digit mode output waveform
"L"
SEL
CLK
DIG
0
DIG
1
DIG
2
DIG
13
DIG
14
DIG
15
OVF
OUT
"L"
SEL
CLK
DIG
0
DIG
1
DIG
2
DIG
3
DIG
4
DIG
15
OVF
OUT
"L"
RESET
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